Electric bell



C. H. BUHL.

ELECTRIC BELL.

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Patented ma 13, 1919.

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ELECTRIC BELL.

Specification of Letters Patent.

Patented May 13, 1919.

Application filed January 16, 1917. Serial No.142,604.

To all whom it may concern Be it known that I, CARL H. BUHL, a citizen of the United States, residing at Cleveland, in the county of Guyahoga and State of Ohio, have invented certain new and useful Improvements in Electric Bells, of

which the following is a specification.

This invention relates to electric bells, and especially to a combination bell and buzzer by means of which selective signals can be given.

By means of the present invention three different sounds can be given, one a bell ring, second a buzzer and third a combined bell and buzzer. Such an arrangement will be found useful in house or other systems to indicate the particular door or location at which the device is operated.

The construction of the bell is such also that it may be used without make and break contacts, by means of a transformer delivering alternating current derived for example from lighting circuits, the use of bell ringing transformers being known, but usually requiring make and break contacts or polarized magnets. The cores of the magnet in the present invention are bent to make substantially a whole horse shoe magnet, giving maximum pulling strength.

In the accompanying drawings- Figure 1 is a diagrammatic view of the bell and circuits.

Fig. 2 is a front elevation of the bell.

Fig. 3 is a section on the line 3-3 of Fig. 2.

Aside from the box or casing at 6 the operative parts of the bell consist of a plate 7 to. which is fixed a pair of upright cores 8 the outer ends of which are bent outwardly as indicated at 9. These cores operate on armatures 10 and 11 the former of which carries a hammer 12 for the bell 13, and the latter of which constitutes the buzzer. armatures are connected to the upturned ends of the base plate 7 by springs 14 to permit vibration.

The lighting circuit at 14 leads to a transformer 15 which is connected on one side by a line 16 to the end of one of the magnet coils 17, and the other side of the trans- The.

former is connected by a line 18 to the end of the other magnet coil 19. 20 is a switch located for instance at the front door of a house, in a line 21 one side of which is connected to the line 16 and the other side of which is connected to the remaining end of the coil 19, and when the switch is closed the coil acting through the core will vibrate the armature 10 and ring the bell, thereby indicating that the operator is at the front door. Another switch 22 is located for example at a side door in a circuit 23 connected to the line 18 from the transformer, and on the other side to the remaining end of the coil 17, and when the switch 22 is closed the circuit will be closed through the coil 17 which will operate the buzzer.

A third switch 24 is located in a bridge circuit 25 which is connected in the lines 21 and 23 and which will close the transformer circuit through both the coils 17 and 19 thereby operating both the bell and buzzer and giving a distinctive sound to show that the caller is for example at the rear door.

A three combination system is illustrated in the drawings, but obviously a two combination system may be used by omitting a third circuit.

The apparatus provides a selective system which will save considerable wiring and parts for bells of this type, a single bell structure and transformer serving to produce the functions indicated.

W I claim:

A selective signal apparatus comprising a pair of electromagnets each having a separate armature, a source of alternating current, lines connecting opposite sides of said sourcev to relatively opposite ends of the coil of each magnet, a pair of switch circuits connected to the other end of each coil and to the line from said source to the other coil, and a third circuit bridged across said switch circuits, to close them both.

In testimony whereof I do aflix my signature in presence of two witnesses.

. CARL H. BUHL.

Witnesses:

JOHN A. BOMMHARDT, S. W. BRAINARD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G." 

